Question about integrating factory alarm with alarm/starter combo.

[Steve190E 2.3]

I have installed and integrated my factory locking system in my 190E to an aftermarket alarm/starter combo. I now have a 1988 300E with factory alarm and would like to integrate it with the remote starter. If I splice into the wire for the power locks off the drivers door, (as I did in my 190E) well it arm and disarm the alarm? I would like to keep the factory alarm as how often do you hear a factory alarm going off. The car has to be broken into first before it goes off. How many times have you driven by a car with an aftermarket alarm and it goes off and no one is around.